The goal of this proposal is to develop a very small, lightweight single channel extracellular electrode amplifier and wireless transmitter and receiver for chronic studies. The amplifier and transmitter will be a compact single board design with integrated antenna. The receiver will demodulate the signal and produce an output that can be directly connected to a data acquisition system. This system would allow long-term recordings from unrestrained animals and open up new avenues of research in neuroscience' including studies of neural correlates of behavior, circadian rhythms, sleep, learning, behavior in natural settings, sensory physiology, social interactions, and epilepsy. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE